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has anyone read this article?

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the article says:


In this study, a plasma cortisol value (measured 15 min after CRH administration) that was greater than 38 nmol/L had 100% diagnostic accuracy for CS, and the Dex-CRH test had superior sensitivity and diagnostic accuracy when compared either with the low-dose dexamethasone suppression test or with the CRH test performed alone (5).


so, i asked on a forum, about conversions, how to convert my .5 mcg/ml cortisol at the 15 min mark to nmol/l and the answer i got was:



To convert between grams and moles, you need the molar mass. The molar mass of cortisol (per Wikipedia) is 362.46 g/mol.


0.5 mcg/mL is also 0.5 mg/L

0.5 mg/L x 1 mol/362.46 g = 0.001379 mmol/L = 1379 nmol/L (should probably be rounded to 1380 or 1400, based on apparent precision of initial value)


this couldn't possibly be right, right? my cortisol could not possibly be that high in relation to the amounts in the study. i checked the answer myself by spending an hour looking up how to convert it. i got the same answer. i'm confoozled. if this were the case, you would think that dr. l's staff wouldn't think i suppressed, right?


do you guys know anything about this?

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Their limit of 38 nmol/L is the same as a limit of 1.38 ug/dL. (38/27.6=1.38) Your report is in ug/mL so their limit in the same units as your report would be 0.138 ug/mL. You're over limit at 0.5 ug/mL.


Conversion of their limit is from nmol/L to ug/dL is accomplished by dividing by 27.6. They reported in mL instead of dL, so move the decimal one place. Another way to look at this is you were 5 ug/dL (0.5 ug/mL) which is larger than 1.38 ug/dL.


Working the other way, your 0.5 ug/mL would convert to 138 nmol/L ( 0.5 ug/mL * 27.6 * 10 = 138)


138 is way larger than 38 = cushing's.

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wow. thanks!


this stuff is so greek to me. i like to think of myself as pretty intelligent, but as soon as numbers enter the picture my iq drops like 40 points. supposedly i have some sort of math learning disability. thanks for helping me out with that.


this is a super interesting study. i think most of us are in this "mild" category. i'm glad i found it.

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